<template>
  <div>
    <router-link tag="div" to="/" class="header-abs" >
      <div class="iconfont header-back-icon">&#xe642;</div>
    </router-link> 
    <div class="header-fixed" v-show="showAbs" :style="opacityStyle">
    <router-link tag="div" to="/" >
      <div class="iconfont abs-header-back-icon">&#xe642;</div>
    </router-link> 
      景点详情
    </div>
  </div>
</template>

<script>
export default {
  name: "DetailHeader",
  data() {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  activated() {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated() {
    window.removeEventListener('scroll', this.handleScroll)
  },
  methods: {
    handleScroll(){
      const top = document.documentElement.scrollTop
      if(top > 60){
        let opacity = top/140
        opacity = opacity > 1 ? 1 :opacity
        this.opacityStyle = {opacity}
        this.showAbs = true
      }else{
        this.showAbs = false
      }
      console.log();
    }
  },
};
</script>

<style scoped lang="stylus">
@import '~styles/varibles.styl';
.header-abs 
  position: absolute;
  left: 0.2rem;
  top: 0.2rem;
  width: 0.8rem;
  height: 0.8rem;
  border-radius: 0.4rem;
  background: rgba(0, 0, 0, 0.8);
  text-align center
  line-height .8rem
  .header-back-icon
    color #ffffff
    font-size .4rem
.header-fixed
  z-index 2
  position fixed
  top 0
  left 0
  right 0 
  overflow hidden
  height $headerHeight
  line-height $headerHeight
  text-align center
  color #fff
  background $bgColor
  font-size .32rem
  .abs-header-back-icon
    position absolute
    top 0
    left 0
    width .64rem
    color #fff
    font-size .4rem     


</style>